Abstract: Aim: To investigate the protective effect of lactosucrose (LS) on the plasma antioxidant system in TNBS-induced colitis rats. Methods: A total of 32 female SD rats were randomly divided into 4 groups: normal control group, model group, LS group and SASP (sulfasalazine) group. The other 3 groups received TNBS induction except the normal control group and were orally administrated with normal saline (10 mL/(kg ·d)), LS (250 mg/(kg ·d)) or SASP (250 mg/(kg ·d)) once daily for 3 successive weeks. At the end of the administration period, all rats were scarified for determination of colon mucosadamage index (CMDI), the activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), inducible nitric oxide synthase (iNOS) and myeloperoxidase (MPO) and malondialdehyde (MDA) level. Results: Compared with the model group, the activities of SOD and GSH-Px in the LS group were increased significantly and could resume their normal levels. The LS group exhibited significantly higher GSH-Px activity when compared with the SASP group and significantly lower CMDI and MPO and iNOS activities when compared with the model group, especially that MPO could be restored to its normal level. Conclusion: LS is capable of improving antioxidant function in the plasma of colitis rats and decreasing the activity of iNOS and inflammatory cell immersion.

Key words: lactosucrose, ulcerative colitis, free radical, antioxidation